JPH0790215A - Aqueous marker ink for white board - Google Patents

Abstract

PURPOSE:To readily wipe off a mark or a letter on a writing surface by using a dry-type eraser in either case the mark or the letter is undried or dried. CONSTITUTION:At least, water as a solvent, a processed pigment 2 and dextrin 1 respectively mixed therein are contained and further a surfactant, in addition to the processed pigment 2 and the dextrin 1, is mixed in the solvent so as to reduce the adhesive force of the dextrin 1 to the writing surface of a white board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based marker ink used for a whiteboard having an ink-impermeable writing surface, and in particular, it is a white ink capable of easily wiping the handwriting on the writing surface. Water-based marker ink for board.

[0002]

2. Description of the Related Art Most of the whiteboard markers that are generally available on the market are so-called oil-based markers that use an organic solvent such as alcohol. The oil-based marker is odorous when writing, depending on the volatile organic solvent used. However, it is a problem from the viewpoint of environmental hygiene and safety in terms of toxicity and flammability, which is a hindrance when used in general households and schools. Further, the oily marker lacks in storage stability such that the solvent is likely to evaporate during storage and deterioration of quality such as fading is likely to occur.

Therefore, in recent years, many water-based markers which are excellent in safety and storage stability have been proposed in place of the oil-based markers using an organic solvent, but these markers are used in a dry environment (for example, humidity). Is under 55%)
If you leave your handwriting on the writing surface for a few days, you will not be able to wipe it off easily with a dry erasing material such as a dry cloth, felt, or soft paper. It was something that had to be wiped off.

In order to deal with such drawbacks, the prior arts, for example, Japanese Unexamined Patent Publication No. 1-11174, No. 1-174577, No. 1-188576, No. 1-252681, Like the water-based marker inks disclosed in JP-A-2-117975 and JP-A-2-124985, it can be easily wiped off with a dry erasing material even after the handwriting is completely dried on the writing surface of the whiteboard. There are things that can be done.

Further, when the writing surface of the whiteboard has minute recesses or pinholes, a colored film remains on the recesses or pinholes and cannot be completely erased by simply wiping the writing surface. Therefore, there is a method in which resin particles are dispersed in the ink so that the handwriting can be easily wiped off by a dry erasing material by the action of the resin particles (for example, Japanese Patent Laid-Open Publication No. Sho-Kaiyo). 63-145383
Japanese Patent Laid-Open Publication No. 1-174577).

[0006]

However, the above-mentioned conventional water-based marker ink has a problem in that when the writing surface of the whiteboard is wiped off with a dry erasing agent while the handwriting is still undried. It has a problem that it may spread upward and contaminate it. This is important because water, which is a solvent for the water-based marker ink, has poorer drying properties than an organic solvent, and is often wiped off after writing before the handwriting is still dry.

In the case of resin particles dispersed in ink, the handwriting adheres to the writing surface of the whiteboard due to the adhesiveness of the dispersant (also binder) of the pigment dissolved in the solvent. However, there is a problem that the handwriting cannot be easily wiped off.

Examples of pigment dispersants (also binders) include polymers such as condensation polymers and addition polymers, and soluble synthetic resins. Generally, pigments are dispersed in a solvent to make clear handwriting. However, at the same time, it has adhesiveness to the writing surface, and if the addition amount is large, the adhesiveness to the writing surface becomes strong.

Further, when the handwriting with the ink containing such a dispersant (also a binder) is completely dried,
Even if you wipe it off, only the pigment may fall off and the polymer and soluble synthetic resin may remain attached to the writing surface, resulting in the writing area appearing to be scratched and the writing surface contaminated. There is also a problem that it is done.

Therefore, in the present invention, whether the handwriting on the writing surface is undried or completely dry, the handwriting can be easily wiped off with a dry erasing material,
Further, by providing a water-based marker ink for a whiteboard, the adhesiveness to a writing surface is weakened by weakening the adhesiveness due to a dispersant (also a binder) dissolved in a solvent, and the handwriting can be easily wiped off. The purpose is to

[0011]

The aqueous marker ink for whiteboard of the present invention contains at least water as a solvent, and a processed pigment and dextrin mixed therein, and further, this processed pigment and In addition to dextrin, a solvent was added to the solvent to weaken the ability of dextrin to adhere to the whiteboard writing surface.

Here, as the processed pigment, for example, a resin processed pigment composed of a pigment and a resin dispersant, an organic fluorescent pigment, or the like is preferably used. The pigment may be either an organic pigment or an inorganic pigment. Examples of the organic pigment include phthalocyanine-based, dioxazine-based, anthraquinone-based, azo-based, condensed polyazo-based, metal complex salt-based, perinone-based, perylene-based and quinacridone-based pigments. Inorganic pigments include carbon black and iron oxide, and fluorescent pigments may be used in addition to ordinary color pigments. The resin dispersant is used to disperse the pigment in a solvent, and a polymer such as the above-mentioned condensation polymer or addition polymer or a soluble synthetic resin is used.

The particle size of these pigments is preferably from 0.1 to several microns, and if it is smaller than 0.1 micron, it may undesirably contaminate the writing surface depending on the material of the whiteboard. On the other hand, if it is larger than a few microns, there is a problem in the storage stability of the ink itself, and the sedimentation of the pigment is observed, which is not preferable.

Further, the processed pigment is 40 to 50% by weight, preferably 44 to 50% by weight in the case of the organic fluorescent pigment in the ink composition.
It is in the range of 47% by weight. This is because when it is lower than 40% by weight, the color becomes light, and when it is higher than 50% by weight, water repellency and other troubles occur. Further, in the case of a resin-processed pigment, it is 20 to 35% by weight, preferably 25 to 30% by weight in the ink composition.
It is in the range of% by weight. This is because when the content is lower than 20% by weight, the color becomes light, and when the content is higher than 35% by weight, the setting property appears on the writing surface of the whiteboard with the resin-dispersed pigment or the like although it depends on the kind of the pigment.

Next, the dextrin preferably has a viscosity of not more than 45 cps (50 ° C.) in a 50% aqueous solution.
The amount thereof is in the range of 4 to 10% by weight, preferably 4.9 to 7.9% by weight in the ink composition. This is because when it is less than 4% by weight, there is a problem in the storage stability and erasability of the ink, and when it is more than 10% by weight, it becomes slightly difficult to wipe off.

Subsequently, the surface active agent is a surface active agent for the purpose of assisting the peeling of the handwriting on the writing surface, and is a surface active agent for pigment contained in the pigment in advance (for example, the above-mentioned resin dispersion). Different agents are used depending on the type. For example, surfactants include cationic surfactants, anionic surfactants, nonionic surfactants, etc. If the surfactant for pigments is cationic, the surfactant is also a cationic surfactant. If the surfactant for pigments is anionic or nonionic, the surfactant may be either anionic or nonionic.
This surfactant is contained in the ink composition in an amount of 2 to 7% by weight, preferably 2.6 to 5% by weight. this is,
When it is less than 2% by weight, it is difficult to obtain uniform handwriting, and when it is more than 7% by weight, when trying to wipe the handwriting, a part of the handwriting spreads and it becomes difficult to erase it once.

In the case of the nonionic surfactant, an ether type nonionic surfactant having high water solubility and high penetrability is desirable, and examples thereof include polyoxyethylene alkyl ether, polyoxyethylene higher alcohol ether and polyoxyethylene nonylphenyl. Ether or the like is used.

The aqueous marker ink of the present invention also comprises
Various additives may be added, and one of them is a highly hydrophilic surfactant used in general marker inks. As shown in FIG. 3, this is a batting filter inside the marker 5. It is used to improve the suction performance of No. 6, specifically, polyoxyethylene sorbitan monooleate and the like. The amount thereof is in the range of 0 to 1% by weight, preferably 0 to 0.1% by weight in the ink composition. If it is higher than 1% by weight, the dryness of the handwriting will be affected, which is not good.

Further, a surface tension lowering agent may be added as another additive in order to enhance the outflow performance of the ink from the chip 7. Specifically, a silicone oil emulsion type defoaming agent having excellent water dispersibility is used,
The amount thereof is in the range of 0.01 to 1% by weight, preferably 0.02 to 0.1% by weight in the ink composition. This is because when it is less than 0.01% by weight, there is a problem in the suction of the ink into the chip 7 and the outflow of the ink from the chip 7, which is 1% by weight
If it is higher, water repellency is likely to occur in the handwriting and the physical properties of the ink are deteriorated.

[0020]

As described above, the aqueous marker ink for a whiteboard of the present invention contains at least water, which is a solvent, and the processed pigment and dextrin mixed therein. Among these, dextrin is It is soluble in water and its specific gravity is as high as 1.06 (22 ° C) in a 15% aqueous solution, so it has viscosity, and as a result, the dispersed pigment has excellent storage stability.

After writing, the film of this ink was processed so as to fill the gaps between the dextrin 1 particle aggregates having a diameter of about 10 microns on the writing surface of the whiteboard as shown in FIG. 1 (a). Pigment 2 in a dispersed state adheres to the writing surface of the whiteboard. Since the adhesiveness of the dextrin on the writing surface is weaker than that of the resin-processed pigment, it can be easily wiped off with a dry erasing material. The dryness of the handwriting is improved as compared with the conventional water-based marker, which is considered to be because dextrin retains water of crystallization at the time of crystallization.

Further, even when the ink is not dried, the handwriting can be easily wiped off by the weak adhesion of dextrin. Even when the processed pigment contains a resin dispersant having an adhesive property, most of the dry film adheres to the writing surface via dextrin, which does not hinder wiping off. The same applies even when the ink has not been dried.

Further, the surfactant has a function of making the dextrin particles having a diameter of about 10 microns into fine particles having a diameter of 3 to 5 microns, and as shown in FIG. 2 (b),
The processed pigment 2 is more finely dispersed by the fine dextrin 1a particles, and as a result, the ink forms uniform handwriting on the writing surface. this is,
This is because if the dextrin particles are large, water repellency may occur in which some particles stick to each other to form a gap between the other particles, which may not form uniform handwriting.

Further, since dextrin is in a finely dispersed state by the surfactant, the adhesion area to the writing surface is reduced, which makes it easy to wipe the handwriting. Further, as shown in FIG. 2, the surfactant is a liquid at room temperature and forms a weakly adhesive film 4 between the writing surface of the whiteboard 3 and the mixture of the dextrin 1 particles and the processed pigment 2. As a result, the ability of dextrin to adhere is weakened, making it easier to wipe the handwriting on the writing surface.

The necessary conditions for the whiteboard marker are: a. Good suction and outflow of ink by the tip b. Intake of ink in the batting filter is good c. Be able to write evenly and evenly on the letters d. Easily erase written characters e. Do not set the letters on the writing surface for a long time f. The ink itself is stable with little change over time g. There are items such as good dryness of written characters. Regarding a and b above, the action of various additives, regarding c, d and e, the action of dextrin and surfactant, and regarding f, the dextrin. Is secured by the action of. Although g is inferior to the oil-based marker using an organic solvent, it is improved by the above-mentioned early drying property of dextrin as compared with the conventional aqueous marker.

[0026]

〔Additive〕

Aqueous marker ink (yellow fluorescent) 100 g was prepared from a 10% aqueous solution of a surface tension reducing agent 0.6 g (for outflow from a chip) and a highly hydrophilic surfactant 10% aqueous solution of 0.6 g (for sucking a batting filter). .

B. Resin-processed pigment (black) 32 g Dextrin 15% aqueous solution 63.2 g Nonionic surfactant 24 g [Additive] Surface tension reducing agent 10% aqueous solution 0.8 g (for outflow from chip) to aqueous marker ink (black) 120 g It was created.
In addition, all the above-mentioned% show weight%.

The above is specifically described below.・ Fluorescent pigments [EX-LemonYellow: Shin Roihi Co., Ltd.] ・ Resin-processed pigments (black) [WMBK-5: Orient Chemical Industry Co., Ltd.] ・ Dextrins [Amycol No.1: Nittei Chemical Co., Ltd.] ・ Nonionic interface Activator (polyoxyethylene higher alcohol ether) [Score Roll 700: Kao Corporation] ・ Surface tension depressant (for outflow from chips: Silicone emulsion defoamer) [Shin-Etsu Silicone KM-90: Shin-Etsu Chemical Co., Ltd. Co., Ltd.) ・ Highly hydrophilic surfactant (for suction of batting filter)
[Leodol TW 0120: Kao Corporation] Nonionic surfactant [Score Roll 700] is 20
It is in the state of a weight% aqueous solution.

Subsequently, in the production method of A, first, 32.8 g of a 15% aqueous dextrin solution is weighed into a beaker, and 46 g of a yellow fluorescent pigment is added and mixed at room temperature under stirring, and then the nonionic interface is added. 20 g of the activator was added and dissolved sufficiently with stirring, and the surface tension reducing agent was added to this mixed solution.
0.6 g of 10% aqueous solution, followed by 10% of highly hydrophilic surfactant
By adding 0.6 g of the aqueous solution and sufficiently stirring and mixing, 100 g of the above-mentioned yellow fluorescent water-based marker ink is prepared.

In the production method of B, first, 63.2 g of a 15% aqueous dextrin solution is weighed in a beaker,
32 g of a resin-processed pigment (black) is added and mixed at room temperature under stirring, and then 24 g of a nonionic surfactant is added and sufficiently stirred to dissolve, and a 10% aqueous solution of a surface tension lowering agent is added to this mixed solution. 120 g of the above black aqueous marker ink is prepared by adding 8 g and thoroughly stirring and mixing.

Next, regarding the characteristics of the above A and B water-based marker inks, when the A and B inks were respectively put in the marker pens and written on the writing surface of the whiteboard, both inks appropriately flowed out from the tip. I was able to write smoothly, and the handwriting was uniform without ink smearing or unevenness.

Further, when the cloth was wiped with a felt (dry erasing material) immediately after writing, both the inks A and B could be easily erased without spreading the ink on the writing surface of the whiteboard. In addition, after writing the handwriting for a long time (about 40
When left for a day and then wiped with felt, both the inks A and B could be easily erased, just like immediately after writing, and were not set on the writing surface.

[0033]

The aqueous marker ink for whiteboard of the present invention has the processed pigment and dextrin dispersed or dissolved in water which is a solvent, so that the storage stability of the pigment can be improved by the dextrin. Since the weakly adherent dextrin adheres to the writing surface, this handwriting can be easily and completely wiped off with a dry erasing material regardless of whether the handwriting is undried or completely dried. It is possible to prevent the stain on the writing surface that occurs when the ink is not dried when wiped, and the stain on the writing surface due to the pigment dispersant that occurs after the ink is dried. In addition, since the present invention uses water as a solvent, there is no defect such as evaporation of the solvent from the chip like a conventional alcoholic marker, so-called dry-up and fading, and moreover, an odor compared with an oil-based marker. It has no toxicity or flammability, is excellent in environmental hygiene and safety, and can be used with peace of mind in homes and schools.

Further, since the surfactant finely disperses the dextrin particles to disperse the pigment more finely, the pigment can form a uniform handwriting, and the surfactant is weak on the writing surface. By further reducing the dextrin's ability to adhere to form an adhesive film, the handwriting can be more easily and completely wiped off by the dry erase material.

[Brief description of drawings]

FIG. 1 is an enlarged view illustrating a state of dextrin particles and a processed pigment on a writing surface according to the present invention. (A) does not contain a surfactant, (b) contains a surfactant. It shows the time.

FIG. 2 is a sectional view in the state of FIG. 1 (b).

FIG. 3 is a cross-sectional view of a whiteboard aqueous marker.

[Explanation of symbols]

 1,1a ・ ・ ・ Dextrin 2 ・ ・ ・ Processed pigment 3 ・ ・ ・ Whiteboard 4 ・ ・ ・ Nonionic surfactant film 5 ・ ・ ・ Marker 6 ・ ・ ・ Batting filter 7 ・ ・ ・ Chip

Claims (2)

[Claims] 1. A water-based marker ink for a whiteboard, which contains at least water as a solvent and a processed pigment and dextrin mixed therein. 2. In addition to the processed pigment and the dextrin, a surfactant for weakening the adhesion of the dextrin to the whiteboard writing surface is mixed in the solvent. Water-based marker ink for whiteboard.